1. What is Hydro Test Pressure?

Definition: Hydrostatic test pressure is the pressure applied to a system or component to verify its strength and leak tightness.

Purpose: It ensures the integrity of pressure vessels, piping systems, and other components before they are put into service.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{test} \) — Test pressure (psi)
• \( P_{design} \) — Design pressure (psi)
• \( S_{test} \) — Allowable stress at test temperature (psi)
• \( S_{design} \) — Allowable stress at design temperature (psi)

Explanation: The formula accounts for the design pressure with a 1.5 safety factor and adjusts for material stress at different temperatures.

3. Importance of Hydro Test Pressure Calculation

Details: Proper calculation ensures the test is rigorous enough to verify integrity without overstressing the components.

4. Using the Calculator

Tips: Enter the design pressure, stress at test temperature, and stress at design temperature. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a 1.5 multiplier in the formula?
A: The 1.5 factor provides a safety margin to ensure the test pressure exceeds normal operating conditions.

Q2: Where can I find stress values at different temperatures?
A: Material stress values are typically found in ASME codes or material specification sheets.

Q3: How long should a hydro test be maintained?
A: Typically 10-30 minutes, but consult applicable codes for specific requirements.

Q4: What's the difference between hydro test and pneumatic test?
A: Hydro tests use liquid (usually water) while pneumatic tests use gas (usually air). Hydro tests are generally safer.

Q5: Are there code requirements for hydro test pressure?
A: Yes, ASME B31.3 and other codes specify requirements based on system type and service.